Saudi-led coalition forces in Yemen killed more than 800 al-Qaida fighters on Sunday in a single attack on a southeastern town held by the militant group for the past year, according to the coalition command.

The death toll claimed by the coalition could not be independently verified.

The official Saudi Press Agency said Monday Yemeni fighters backed by Arab coalition air forces launched an offensive on the al-Qaida stronghold in the port city of Mukalla.

Military sources told the French news agency AFP the coalition forces entered Mukalla “and were met by no resistance from al-Qaida militants who withdrew west.”

The source also said an oil terminal was recaptured during the offensive.

Several al-Qaida leaders were among those dead, and all militants who were not killed in the attack fled, the coalition command said in a statement.

The military action came as part of an international effort to support the Yemeni government and to exert influence over the Yemeni cities that are under the control of al-Qaida, the statement said.

The coalition also said it hopes to “allow intensifying humanitarian relief efforts in those cities and alleviate suffering of the brotherly people of Yemen.”

It is not known whether any civilians were killed during the fighting.